Chevrolet Repair: can u help me out, fuel filter, horsepower

Question
Ok i've got a chevy 1996 Chevy S-10 2.2 liter 4 cylinder and i was driving home last night and i noticed that my truck was running really slow up the mountain i usually can run 70-75mph up it but last night i wasn't even breaking 50mph it sounds louder and it sounds like the manifold is loose because it's making an awful rattling noise but when i got home i popped the hood and it looked like there was oil coming out of the side of the head, is that the cause of my truck to lose horsepower, and how much will it cost to fix it?

Answer
Hi Chris, You need to have this looked at. I can only guess on this one. The cat-con could be plugged or your fuel filter could be plugged. The oil might just be from you pushing the engine and it can't get going. If the cat is plugged it will cause a lot of exhaust back pressure. I would take it to have some one look at to find out for sure.  Sorry I can't help more on this one:(

Mark